This invention relates to medico-surgical and sanitary articles, and materials.
The invention is more particularly concerned with w.c. disposable articles, such as ostomy or urine incontinence bags, diapers, sanitary towels and so on and with materials from which they can be made which facilitate disposal of such articles.
Attempts have been made recently to develop ostomy and urine bags which can be disposed of by flushing in a water closet to avoid the need to make special disposal arrangements which can be inconvenient, embarrassing and unhygenic.
Disposable bags generally have an outer water soluble or dispersable layer and an inner water resistant layer. The outer layer provides mechanical support for the inner layer so that, when the bag is dropped into turbulent water in the pan of a water closet, the outer layer is quickly broken up. The inner layer prevents the contents of the bag attacking the outer layer in use but, once the outer layer is broken up on disposal, the inner layer does not have sufficient mechanical strength in itself to cause blockage on flushing the water closet. An example of such a bag is described in GB No. 2 83 762B.
Although such bags can be used satisfactorily, the fact that the outer layer is damaged by contact with water means that the user has to take special precautions to ensure the outside of the bag does not become wet. This can be especially inconvenient with bags which are worn long-term, for two or more days, such as is usually the case with ileostomy bags. The use of such a bag can make washing difficult.
An alternative form of bag is described in EP 0142950A which is made of 3-hydroxybutyrate film either in a laminate with a water soluble film as an outer layer, or entirely from 3-hydroxybutyrate. Such a material remains intact when in contact with water or body waste, but is broken up if the pH is raised to about 12. The bag described is disposed of by adding a base material to the contents of the bag so as to raise the pH of the contents to at least 12 so that it breaks up when agitated in a water closet pan. It will be appreciated that the laminated form of construction does not avoid the disadvantages referred to above of having to keep the outside of the bag dry. Where, however, the bag is made entirely of 3-hydroxybutyrate, this can be insensitive to external wetting. The method of disposal of such a bag, that is, by adding a base material to the contents of the bag, is not entirely satisfactory. Firstly, it can be distasteful to some users to have to open the bag in order to add the base chemical to it. Also, break up of the bag can be slow. This is because the bag will only be broken up where it is contacted by the alkali. If the bag is only partially full, as is usually the case, it follows that regions of the bag may remain untouched by the alkali. Furthermore, solid material such as faeces in the bag, will mask parts of the bag from attack by the alkali and thereby delay disposal. Also, if the contents of the bag are acid the strength of the alkali must be sufficient to counteract this which may require the use of a hazardly active alkali.
Similar problems are met with other articles, such as diapers. These preferably have an outer water-impermeable layer to reduce leakage, but this layer remains intact in a water closet, making disposal of such diapers more difficult.